This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The BTV-1 cores are double-layered (two protein layers) and are ~70nm diameter. There may be some contaminating single-layered particles which are ~52nm diameter, and these lack the VP7 protein. The transcription complexes are located inside the inner layer at the 5 fold symmetry axes (although possibly not at all 12 - the genome consists of just 10 segments). The sample appears to be 100% pure on an SDS PAGE gel and is ~0.1-0.2 mg/ml. Much higher concentrations can be achieved by ultracentrifugation of a larger preparation in the future if necessary. Storage at 4C for months is possible. The core particles (lacking the outer capsid) are much more stable than the complete virion (and easier to purify). The virus is not hazardous to humans, but decontamination with bleach is essential to prevent the potentially infectious cores from infecting the insect vector (which exists in the US) or directly coming into contact with sheep, cows, goats, or wild ruminants.